Burner assemblies



Sept. 3, 1968 M. R. QUIRK 3,399,950

BURNER ASSEMBLIES Filed June 23, 1967 4 Sheets-Sheet 1 Sept. 3, 1968 M. R. QUIRK 3,399,950

BURNER ASSEMBLIES Filed June 23, 1967 4 Sheets-Sheet 2 FIG. 4

Sept. 3, 1968 M. R. QUlRK BURNER ASSEMBLIES 4 Sheets-Sheet 5 Filed June 25, 1967 Sept. 3, 1968 M. R. QUIRK BURNER ASSEMBLIES 4 sheets-sheet 4 Filed June 23, 1967 FIG. 6

United States Patent 3,399,950 BURNER ASSEMBLIES Martin Richard Quirk, Lee-on-Solent, England, assignor to John I. Thornycroft & Company, Limited, Portchester, Hampshire, England, a British company Filed June 23, 1967, Ser. No. 648,402 Claims priority, application Great Britain, June 30, 1966, 29,350/ 66 8 Claims. (Cl. 431-153) ABSTRACT OF THE DISCLOSURE A liquid or gaseous fuel burner assembly for industrial applications comprising a shuttle-like burner head movable in guide means from a retracted inoperative position to a forward operative position within a boiler, the burner head being removable from the guide means when in its retracted position for cleaning and maintenance and connectable to a fuel supply pipe only when in its operative position.

This invention relates to burner assemblies of the type used in industrial applications, by means of which a liquid fuel, for example, oil or a gaseous fuel is ignited. The

heat produced may be used as an intermediary for the ignition of a further fuel, for example, pulverized coal may be used directly for heat transfer, for example, in producing steam. These burner assemblies are particularly applicable for the firing of boilers in electricity generating power stations and for the firing of industrial and marine boilers.

Large industrial boilers sometimes employ pulverised coal as fuel which must be fed into the boiler and there ignited. Such ignition is frequently achieved by several oil burners, all or some of which may be in operation at any given time depending on the desired output of the boiler. A hitherto proposed method of firing has been to pass oil fuel to a burner within the boiler through a tube which extends through the wall of the boiler, to pass combustion air for the burner through a second tube which surrounds the oil fuel tube and to pass the pulverised coal fuel through a third tube which surrounds the oil and air tubes. In this manner, the burner may be maintained ignited by a constant supply of oil fuel and air from outside the boiler, the heat generated by the flame from the burner igniting the pulverised coal fuel as soon as it reaches the flame area.

As previously mentioned, only some but not all of the burners may be in operation at any one time and to prevent direct heat radiation from the centre of the boiler on to such inoperative burners, it has been proposed to arrange the burners so that they may be slightly retracted into the boiler wall. This arrangement involves each burner assembly being retractable and extendable bodily and involves the use of flexible connections outside the boiler for the supply of oil and air to the assembly.

These burners periodically require maintenance for the removal of carbon deposit and, for this purpose, the entire burner assembly including the fuel supply tubes are adapted to be removable from the boiler. After removal, each burner assembly is transported toa site at which maintenance may take place. To enable the removal and replacement of burners, modern boilers are provided with handling equipment in the form of a crane or the like, which equipment adds considerably to the cost of installation of a boiler and as the trend is for boilers to become larger rather than smaller so that their output may be higher, such handling equipment has to be correspondingly larger and more expensive to deal with the longer and heavier burner assemblies.

It is the main object of this invention to provide a ice burner assembly which obviates the necessity of using handling equipment as aforesaid.

The present invention arises from the realisation that the only part of a burner assembly which requires maintenance, other than general maintenance which may only arise perhaps once a year, is the burner head, i.e. that part at which the fuel is ignited and which is subjected to the very high temperatures involved.

According to the present invention there is provided a burner assembly comp-rising a burner fuel supply pipe, a shuttle-like burner head incorporating a burner, guide means for the burner head, means for moving the burner head from an inner operative position to an outer inoperative position and vice versa along the guide means and means for connecting the burner fuel supply pipe to the burner head only when the burner head is in its operative position, the connecting means being disconnectable from the burner head to permit the burner head to be withdrawn to its inoperative position for removal from the guide means.

One embodiment of burner assembly constructed in accordance with the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a shuttle-like burner head in accordance with the invention;

FIG. 2 is a sectioned perspective view of a burner assembly in accordance with the invention, with the burner head in its operative position;

FIG. 3 is a sectioned perspective view similar to FIG. 2 but with the burner head in the retracted inoperative position;

FIG. 4 is a longitudinal sectional view of the inner part of the burner assembly of FIGS. 2 and 3;

FIG. 5 is a longitudinal sectional view of the outer part of the burner assembly of FIGS. 2 and 3; and

FIG. 6 is a cross-sectional view on the lines VI-VI of FIG. 4.

The general arrangement is shown in FIGS. 1 to 3. In FIG. 1 there is shown a shuttle-like burner head 1, which will be described in more detail later, which is capable of movement from its operative position, as shown in FIG. 2, to its inoperative position, as shown in FIG. 3, and vice versa. The burner head 1 moves within a guide tube 2 the inner end 3 of which extends into the boiler and the outer end 4 of which extends to outside the boiler so that access may be gained to the guide tube 2 from the end 4 while the boiler is still in operation. The atomising air tube 5 is fixed to the outer wall 6 of the boiler casing and surrounds part of the guide tube 2 and a combustion air tube 7 is fixed to the inner wall 8 of the boiler casing and surrounds parts of both the guide tube 2 and the atomising air tube 5. A further tube (not shown) surrounds the combustion air tube 7 for the supply of pulverised fuel to the boiler. Stabilisers 9 are fitted between the combustion air tube 7 and a sleeve 10 to impart a swirling motion to the combustion air supplied to the burner in a manner known per se. Lying between the guide tube 2 and the atomising air tube 5 is an oil sup ply pipe 11 which extends through the outer wall 6 of the boiler casing to the operative position of the burner head 1 for the supply of oil to the burner head when in its operative position.

As seen more particularly in FIG. 4, the burner head 1 includes an air atomising oil burner 12 having a peripheral flange -13 for engagement with a shoulder 14 at the inner end of the guide tube 2. The burner head 1 has a rod 15 attached to the burner 12, this rod 15 having a port 16 at its outer end which leads, via a bore in the rod 15, to the burner 12 for the supply of oil to the burner. The rod 15 has a stabilising ring 17 and a 3 boss 18 which carries one end of a sleeve 19, the other end of which is fixed to a piston member 20 which forms a sliding seal with the inside wall of the guide tube 2. The sleeve 19 has an aperture 21 therein (see FIG. 6) through which the means for connecting the oil supply to the burner head is admitted.

As also seen in FIG. 6, the guide tube 2 is provided with projections 22 which register with slots 23 at the side of the burner head 1 so as to maintain rotational orientation of the burner head '1 within the guide tube 2. These projections 22 are positioned at intervals along the length of the guide tube 2.

At the outer end of the burner head 1 is a ring 24 to facilitate withdrawal of the burner head from the guide tube 2 for cleaning and maintenance purposes.

At the outer end of the guide tube 2 is a removable cap 25 held in the closed position by a screw threaded handle 26 in engagement with an arm 27 pivoted at 28. On unscrewing the handle 26 the cap 25 may then be swung to a position remote from the end of guide tube 2 and the burner head I removed from the guide tube 2 by means of ring 24. The cap 25 also acts as a limit stop for the outward movement of the burner head 1.

Lying between the guide tube 2 and the atomizing air tube 5 is the oil supply pipe 11 which, as will be seen from FIG. 5, has an oil supply union 29. This oil supply pipe 11 is capable of axial and rotational movement to connect the oil supply pipe 11 with the burner head 1 and for this purpose the inner end of the oil supply pipe 11 is provided with a cranked extension 30 which is capable of making a self-sealing engagement with the port 16. Longitudinal movement of the oil supply pipe 11 is achieved by operation of double acting air cylinder 31 moving push rod 32 which is connected by union 33 with the outer end of oil supply pipe 11. Near to the inner end of oil supply pipe -11 is a sleeve 34 having a profiled slot 35 therein, the sleeve 34 being fixed by screws 36 to the oil pipe 11. Operating in the slot 35 is a pin 37 carried by the atomizing air tube 5.

When the burner head 1 is being moved to the operative position illustrated in FIG. 4, the cranked extension 30 of the oil supply pipe 11 will be in the position shown in chain dotted lines in FIG. 6. For connecting the oil supply pipe .11 to the burner head 1, the air cylinder 3-1 is operated which causes axial inward movement of the oil supply pipe 11 and because of the co-operation between slot 35 and pin 37, the latter part of the axial movement causes the oil supply pipe 11 and hence the cranked extension 30, to rotate and the cranked extension 30 to move to the position indicated in full lines in FIG. 6, thereby forming a communication to supply oil to the burner 12. Operation of air cylinder 31 in the reverse sense causes a retraction in the oil supply tube 11 and hence the cranked extension 30 will break its connection with the port '16 and will swing away and out of guide tube 2. The burner head may then be retracted.

Forward and return movement of the burner head 1 from the retracted to the operating position and vice versa is achieved by air under pressure and vacuum respectively. Compressed air may be admitted to the outer end of guide tube 2 through port 38 and vacuum may be created at port 38 from a vacuum supply. If desired, two separate ports may be provided but in either case selective operation is possible.

In operation, the cap 25 is moved to its inoperative position and a burner head 1 is inserted at the outer end of guide tube 2. The cap 25 is then positioned and made fast by screwing up the handle 26. When the burner is to be used, air under pressure is admitted through port 38 and this forces the burner head very rapidly to the inner end of the guide tube 2 so that flange 13 abuts shoulder 14. The air cylinder 31 is then operated to move the oil supply pipe 11 forwardly so that the cranked extension 30 co-operates with the port 16 and oil may be supplied through union 29 to the burner 12. The burner 4 may then be fired. When it is desired for the burner to be retracted either to be merely withdrawn from the flame area or to be removed entirely from the assembly for cleaning and maintenance purposes, the air cylinder 31 is operated in the reverse sense to retract the oil supply pipe 11 and rotate the cranked extension 30 out of the path of movement of the burner head 1. Vacuum is then created through port 38 and the burner head 1 is sucked back to its position illustrated in FIG. 3. The cap 25 may then be opened and the burner head removed from the guide tube 2.

The arrangement may be such that the fuel burnt is gaseous, for example, coal or natural gas and the means for ignition of the fuel may be as already known, for example, a gas jet ignited by a hot wire or high tension spark. The manner in which the shuttle-like burner is moved forwardly and rearwardly maybe other than as described above, for example, steam or other fluid or mechanical means such as a screw-drive may be employed or electrical means such as solenoids may be used. Further, the burner head may be withdrawn to ground level by virtue of an extension pipe which may be of a flexible nature being connected to the outer end of the guide tube 2. Also, the invention is applicable to various other types of burners, for example, if a pressure jet burner is used then no atomising air is required and the fuel supply may be connected axially with the burner head. Still further, the retraction or feed of the burner head could be by gravity dependent on whether the firing is inclined up wardly or downwardly.

What is claimed is:

1. In a burner assembly comprising a burner fuelsupply pipe and a burner, the improvement comprising a shuttle-like burner head which incorporates the burner, guide means for said burner head, means for moving said burner head from an inner, remote, operative position to an outer accessible inoperative position and vice versa along said guide means and means located near to the inner position of the burner head for connecting said burner fuel supply pipe to said burner head only when said burner head is in its operative position, said connecting means being disconnectable from said burner head to permit said burner head to be withdrawn to its inoperative position for removal from said guide means.

2. In a burner assembly as claimed in claim 1, the improvement comprising a cranked extension of the burner fuel supply pipe adapted for sealing engagement with a port on the burner head.

3. In a burner assembly comprising a burner fuel supply pipe and a burner, the improvement comprising a shuttle-like burner head which incorporates the burner, guide means for said burner head, means for moving said burner head from an inner operative position to an outer inoperative position and vice versa along said guide means and means for connecting said burner fuel supply pipe to said burner head only when said burner head is in its operative position, said connecting means being disconnectable from said burner head to permit said burner head to be withdrawn from its inoperative position for removal from said guide means, said burner assembly further comprising means for providing axial and rotational movement of the burner fuel supply pipe to effect engagement and disengagement of the said cranked extension and the said port on the burner head.

4. In a burner assembly as claimed in claim 3, the improvement comprising the provision of a pin and a sleeve mounted on said burner fuel supply pipe, said sleeve having a profiled slot whereby rotational movement is imparted to said cranked extension by co-operation of said pin and profiled slot.

5. In a burner assembly as claimed in claim 1, the improvement comprising a guide tube constituting the said guide means, means on the said burner head for providing a sliding seal within said guide tube, a source of air under pressure and a source of vacuum and means for connecting said pressure source and said vacuum source to said guide tube.

6. In a burner assembly as claimed in claim 5, the improvement comprising a series of longitudinally in-line projections on the internal wall of said guide tube which register with slots in the burner head to maintain the rotational orientation of the said burner head within the said guide tube.

7. In a burner assembly as claimed in claim 5, the improvement comprising a removable end cap at the outer end of the said guide tube, said cap forming a stop for outward movement of said burner head and enabling access to be gained to within the said guide tube for the removal therefrom of the burner head.

8. In a burner assembly comprising an oil supply pipe and a burner, the improvement comprising a shuttle-like burner head which incorporates an air-atomising oil burner, a guide tube for the said burner head, an atomising air tube surrounding the said guide tube, a combustion air tube surrounding the said atomising air tube, a source of air pressure and a source of vacuum connectable near to the outer end of the said guide tube for the selective movement of the said burner head to an operative and an inoperative position and a cranked extension at the inner end of the said oil supply pipe for connecting the said burner head to the said oil supply pipe only when said burner head is in its operative position.

References Cited UNITED STATES PATENTS 2,689,001 9/1954 Leysen 15876 2,831,535 4/1958 Lange 15876 3,267,988 8/ 1966 Schott.

FREDERICK L. MATTESON, JR., Primary Examiner.

E. G. FAVORS, Assistant Examiner. 

